The study of the environmental hazards of chemical gas pipeline rupture is of great significance to the design of explosion prevention measures and the development of emergency response programs. Taking a typical overhead gas pipeline as the research object, the environmental hazards of the whole process of natural gas leakage diffusion, jet fire, vapor cloud flash fire and explosion accident development were analyzed. The results show that when designing explosion-proof measures and formulating emergency plans, the explosion risk area should be calculated according to the low wind speed. Natural gas leakage mainly affects the chemical park B area, office buildings A， B， C, street stores A. The downwind direction of the occurrence of jet fire accident 8.7~76.1 m is a high-risk area, affecting the area of the chemical park B area, office buildings B and the street stores A. The area affected by the vapor cloud flash fire is Chemical Park B, Chemical Park A, Office Buildings A, B, C, D, Street Shops A, Residential Area A, the main road and the edge of the Science and Technology Park, so the area should be evacuated in advance of the fire. Natural gas explosion damage area is downwind -47.1~67.2 m, mainly affecting the chemical park B, chemical park A, office buildings B, street stores A, residential neighborhoods A.

In order to further improve the recovery of oil after binary composite flooding in offshore oil fields,based on the development contradiction existing after the binary flooding,combined with the indoor physical simulation experiment,three different combinations of oil displacement systems were designed on the basis of conventional oil displacement agents. According to the characteristics of the reservoir after the binary flooding,three kinds of high concentration polymer flooding,high concentration polymer + two yuan and heterogeneous phase were proposed and compared with the experiment. The results showed that the three experimental schemes showed different degrees of secondary decline in water,the shunt rate of the high permeability layer decreased,and the shunt rate of the medium and low permeability layer increased.The recovery rate of experiment was 13.55%,10.93% and 16.05%,respectively.It provides technical support for subsequent profile optimization and individual well personalized design,which lays the foundation for the completion of a set of recovery technology method system after a set of two yuan flooding.

Principle of litho electric experiment and threedimensional physical simulation system were used to research the swept law of binary. By the pressure recorder and resistivity measuring probe installed on the model, the change of the pressure and saturation in the model was accurately measured and swept law of the binary compound flooding system was evaluated. The results showed that the swept volume of low permeability layer was expanded by the binary system, and the sweep efficiency of the model was also improved. After binary flooding, the unswept areas mainly concentrated on both sides of the mainstream line in the layer of low and middle permeability, and there is unswept areas shunt online between the production wells because of the influence of border and injectionproduction well.